Pneumatic hammer and riveter.



H. H. VAUGHAN.

PNEUMATIC HAMMER AND RIVETER.

(Application fileli Feb. 1, 1901.

(No Model.)

' citizen et the United States,

' UNITED STATES PATENT OFFICE.

Y H? renew or ames I N. i -*1 3 mandamus forming smtime Patent mess s,ated-basa 29; 191m 1,;

, Be'it knownthat HENRY n. vlcnldf, a

Stateof Illincis',

cago',in' the ,c'ountyfcf Co okg U I m and [useful Imhave inventedcertain new pr'ov eine'ntsinlneumatic Hammers andRiveters; and I herebydeclare the fell owing to be a full, clear; and exact-descripticn cfthesame, reference being had to the accompanying drnwings in which- Figurel is'a longitudinal central, section of pneumatic hammer or ,riyeterembodying myin ventien in the preferred fornn Figs.

2, 3,' and. 4 are cross-sectional views taken on .the dotted lines 22,76 3, and 4 4, respectively, l

cf FigQ I. Fig.5 is a. lcngit udinal central section or: a; modificationwherein the sleeve and bushing which form the clearance-space of thecylinder are made integral izgst'eadof separable, as shown in thepreferred conrelates to the c ons tructicnof that class of devices knownas motiveand} mere especially, to that, class wherein '21,.

The main bject :of, my present invention is toppbtainsueh clearancevolnmeiat the ex- ,haust or lower. end 'of" the cylinder as shall ainsure ,substantially atmospheric pressure 35.

beneath -the; piston' at the point compression uiccminexices during thereverse strpke oflth e c pis ton 1 without increasing .the diameter ofin what, are commonly termed hand-ham-' mers o,r' riveters.-

'the cylindier or lengthening the front .end of the piston, both ,ofwhich areobjectionable fTo this end one feature o f i n-y inventionconsistslincombiningwith the cylinder of a constant-pressurepneumaticthammer orri-veter an inserted sleeve andbushinglwhich may beintegralmisspell-able) channeled ofn the perigher'y to fcrin aclearance-space. within 1 the; walls of the1 e;,'l inder, .said sleeve,havinfg airport through which .the'nnder side of the 1 clearance-space;a

.. ,1]; ma .towfacilitate gm leonstructich r;

pressure is admitted to piston .by way. of -said residingat Chithe tllesleeve and bushing are fprefe l-ably inadeseparable and as when so;,censtructedthe sleevemaybe. driven pack or a ri dm we bash ng y a ia iv -ment of the piston'said sleeve is given a movable, thoughsubstantially air-tight, fit with on the li eran bu h the fluid-pressurewhen on will alwaysmaim s im Pr p r l i bfi ee e' ldz ing and preservethe normal strekeer neve- Qrnentoff the iiisten Or hammer, and such acons i ctio emb ie as ondlf aw Qfmy' invention. 1

. W e e as. pea-trite i 'v e'alb h and sleeve are separahle' lprefer -toc'o mbine therewith and with thecylinder afsprin'g or equivalent means*f or naintainin-g' the; relation of the sleeve ito th e bushing whenthe motive fluid is withdrawn; and such a conion'embodies a third, fe uo yiny n i m structien or combinat In p r to i c ea et e ing vel city ot e pistomorhw e n e uc swe g lfceinbine witha constant-pressurepneumatic-hammer cylinder having a clearancespace within its walls,which space has. a pressure-port leading thereto, a piston. having ta,ca'vitypr cf cup form andsdevoid of, throughpcrts; and. suchga.cbnstruction embpdies a fourthfeature of-my invention,

There are, other minor features .oflinvem ,tin, all as will hereinaftermore fully appear,

. I willnowprcceed to describe myfiinventio'n more 'fn1ly,1s0 thatothers. skilled in vtheart to vwhich it .ap'pertains mayapply the. same.

i In the drawings, Aindicates'thehandle of a pneumatic. riveter,providedwith theeusualy niotive-fluidrsupply passage-a, leadingto oneend ofthe cylinder, saidpassage guarded by the spring-closed valveAywhichwalve' isop- I eratedby lever Aito controlthe admission of.thesmotivelfluid toi'the cylinder.

B "ndicatesuthe cylinden: whi'chnmaybe serewediinto the'handle' A and.Tmay be provided with aratchet-deviceb, with which a dog or catch a inthe handle enfgagesito 11001;,

the-parts securely. togethen v The handle A, it will be noted',' eldsesthe upper endicflcylinder-B'o1- thatend througl1 which the motive-fluidpressureisxadmitted,

- and-the opposite end ofthe cylinder B is providedwith a. ferrule 13;

. having a suitable ion catch 1) forholding the removable snaporrivet-die C, so that when the rivet-die O or snap is in position itand the ferrule B constitute' the otherhead of the cylinder. The

snap or rivet-die G has a stem 0, which projects into the cylinder andis. struck by the piston (or hammer) when it delivers its down stroke orblow.

To the extent thus far specified the con-;

' if desired, (see Fig. 5,) but are preferably separable, and, ifseparable, the bushing 1' may be pressed or driven into cylinderflB, so

, as to retain its position therein, especially against rotation, whilethe sleeve 2 may have a movable or sliding, though substantially flhid-pressure in case it 'should be driven back (toward the handle A) byexcessive travel of the piston 3 on its reverse movement, and as a meansof holding said sleeve to its seat' when the fluid-pressure is withdrawna coiled spring orequivalent device, 4 may be interposed between the"free end of said sleeve 2 and the head of the cylinder or the handle A,which constitutes said'cylinder-head.

If the'sleeve 1 and bushing 2 are formed integral or as a single piece,(see Fig. 5,) in

which case said part should be removably fitted into the cylinder B,(and, if desired, may be spring-pressed, as shown in Fig. 1,) a dowelpinb or equivalent provision should be made to prevent any rotary movementof the parts land 2 within the cylinder B in-order that theports whichextend through the bushing may always register with those in .theoutershell or cylinder B.

Whetherseparately formed or integral that portion of the cylinderslining which has been termed bushing '1 will at its upper part or partcorresponding to the middle of cylinder B be provided with a series oflongitudinal grooves or channels 1 and below said central section may beof reduced external diameter, so as to form an annular channel orclearance-chamber 5, (see Figs. 1 and 4,) which communicates with thepiston-chamber below by ports 5!, or in other suitable manner. Whilethis clearance-chamber 5 within the walls of the cylinder is shown as anannular chamber, it need not necessarily be of such form; but whateverits form it should have a clearance volume equal to at least twentyfive(25%) per cent. of the volume of that portion of the cylinder in whichthe lower head of the piston acts, 'or, iu other words, a clearancevolume equal to at least twenty five (25%) per cent. of the displacementof the piston during one stroke. Opposite that portion of bushing 1having the longitudinal peripheral grooves orchannels 1 are a series ofports which extend through the walls of the bushing and when the bushingis in proper position within the cylinder B register with the ports 13and B of said cylinder, the first of said ports B 13 beingexhaust-ports, while that marked B is simply a provision to relieve anypossible pressure on the piston during the reverse movement andafter theports B have been covered.

The sleeve or that portion of the cylinderlining which has been termedthe sleeve 2 will be formed at its upper end of adiameter suitable forits support within the cylinder B,

(or: with what may be termed a collar 2*.)-

and if made separate from the bushing 1 will also be reduced at itsinner end, as at 2", so as to enter the bushing to a limited extent oruntil arrested by the shoulder 29, which will 1 and 2.

The reduction of the external diameter of i the sleeve-section 2 formsan annular chamair-tight, fit, so as to be forced forward by the her6,which communicates with the clearancechamber 5 through thelongitudinal channels or passages 1 and with the interior of thecylinder about midway o't sleeversection 2 by means of apressure-port-7, which establishes direct communication with theconstant-pressure chamber of the cylinder and is the suplyport for theopposite end of the cylinder determine the relation of the separableparts there b ing no ports or passages through the-piston v It will benoted. that the internal diameter of the. bushing-section 1, and thesleeve-section are difierent, that of the bushing being the greater, soas to call for a difterential'piston 3, presenting a lesser area totheconstantpressure chamber, or thatend of the cylinder where thefluid-pressure is admitted, and a greater area on the striking end ofthe piston or hammer or the exhaust end of the cylinder. Where asolidpiston or plunger is employed its blow will be the same as the energyback of the piston,- and in carrying out m y, invention I hollow out thepiston, as indicated by the dotted lines in Fig. 1, which will increaseits velocity and augment its blow, as the energy ofthe blow isproportionate to the weight occupied by the square of the velocity. There areno ports or passages through the piston, which is thus distinguishedfrom somewhat similar shaped pistons which have supply or exhaust portstherein or therethrough.

The construction being substantially such ashereinbefore pointedout, thedevices will operate as follows: The hammer or piston 3 being in theposition shownin Fig. 1 of the drawings--that is tosay, in the positionit occupies when its blow has been delivered on the stem of snap C-andthere being a constant pressure of the motive fluid on the upper orlesser area of piston 3, the motive fluid will pass through port 7 ofsleeve 2, thence through channels 1" of bushing 1 into clearance-chamber5, and through ports 5 to 45 head of the piston having the lesser area,the

the opposite end or under side of the piston or that head having thegreater area, and will force the piston back until it shall have passedthe exhaust-ports 13*, before which time the upper end of the piston3will have covered the supply-port 7 of sleeve 2, and the further returnmovement of the hammer or piston is due 'to the expansion of the motivefluid. The instant the piston? in its upward or return movement uncoversthe ports l3 13 the} exhaust occurs, and owing to the increasedclearance volume secured by reasonof the annular chamber 5 within thewalls of the cylinder 13 and formed by the bushing l, whichclearan'ce-spaceis also measu rablyaugmented by the annularchamber 6around the sleeve 2, the pressure on the lower end of the piston 3-isreduced to substantially atmospheric pressure at the point compressionsubsequently commences.

A great value of the movable sleeve 2, in-

combination with cylinder and a difierential piston, is that it permitsthe introduction of the piston from the handle end or back end of thecylinder, and 'thus avoids vthe formation of an extra joint at the frontend of the cylinderor under side of the piston.

Having thus described my invention, what I'claim, and ent, is-

1. In a motive-fluid hammer or riveter,'having a differential piston andprovision for maintaining constant pressure on the head of said pistonhaving the lesser area, the combination with said piston of a cylinderhit-V'- ing within its walls a clearancechamber which communicates withthe interior of the cylinder on the side of the piston-head havingthegreater area, means for admitting pressure to the under side of thepiston, and

- anexhaust-port in said 'cylinder,substantially as and for the purposesspecified.

2, 'In a motive-fluid hammer or'riveter, having a dilferential pistonand provision for maintaining constant pressure upon that combinationwith said piston of a cylinder having a detachable lining channeled onits periphery to form a clearance-chamber which communicates with thecylinder and provided with ports which communicate withthe cylinder atits opposite ends,substantially as and for the purposes specified.

3. In a motive-fluid hammer or riveter havinga dilferehktial pistomthecombination with said piston o a cylinder having a clearancechamberwithin its walls, and a movable sleeve in that portion ofthe cylinderwhich con- 'tains the'head of the piston having the lesser area saidsleeve provided with a port, substantially as and for the purposesspecified.

desire to secure by Letters Pat 4. In a moti ve-iluid hammer or rivoter,havin g a diiferential piston, thecombination with within that portionof the cylinder which contains the lesser head of the piston,substantially as and for the purposes specified.

der and a movable sleeve or lining section 6. In a motive-fluid hammerorriveter, the

combination with acylinder and piston, ot' an inserted movablelining-section for the cylinder and means for maintainingconstantmotive-fluid pressure upon one head of the piss ton and on theend of the inserted sleeve which surrounds said piston-head,substantially as and for the purposes specified. Inaconstantpressuremotive-fluid ham mer or riveter, the-combination of a hollow ortubular differential piston devoid of ports therethrough, and a cylinderhaving a clearance-'chamb'erwithin its walls, an exhaustport andsuitable. supply-ports betweenlthc opposite ends of saidclearance-chamber and the cylinder, substantially as'and for thepurposes specified.

8. In a motive-fluid hammer or rivet'er,-the combination with a suitablecylinder,- of a hollowor tubular dilferential piston -devoid of portstherethrougnand suitable port forms:

tions for admitting motive-fluid pressure to the under side of saidpiston, substantially as and for-the purposes specified.

9. In a motive-fluid hammer or riveter, having a diiferential piston andprovision for maintaining constant pressure on the head ofthepistonhaving the lesser area,-the combination with said piston of a.cylinder having within its walls a clearance-space which com' municateswith that end of the cylinder which contains the greater head of thepiston, said clearance-space between the. cut-off point on the pistonand the ports which open into the lower end of=the cylinder having aclearance volume equal to at least twenty-five per cent.

for the purposes specified.

January, 1901. p

HENRY I-I. VAUG'I'IANL Witnesses: i

' FRED'KIRGIS, WALTER 'ScnoMEcnn.

'of'the displacement of the greater head of the: 5 piston during onestroke, substantially as'and In testimony whereof I aiiix my signature,v in presence ,of two 'witness'espthis lfith, day of

